During developing this blog I invented one more bicycle for Caching Symfony controller. But first of all lets see how did this task arose.

For example, I have a list of categories, archives and tags on a sidebar. It is relatively easy to get last one (one query), but much harder to get list of categories and archives. For getting categories, we need to select trees (categories can be nested) and using subqueries inside queries get number of articles in every category (result is a little bit monster). For getting the archives list, we need iterate over all articles and gather list of years/months. All this actions isn't very sophisticated, but it is better to avoid them.